The key hypothesis of this proposal holds that the connective tissue activation process contributes to the events of inflammation, influencing both the reparative (proliferative) and destructive components. The long term objectives will be: 1) to define the molecular characteristics of two potent initiators of connective tissue activation, connective tissue activating peptides III and V, (CTAP-III and CTAP-V), 2) to assess the relevance of CTAP-III and CTAP-V to the inflammatory process and rheumatic diseases, and 3) to define the mechanisms by which these CTAPs initiate and sustain connective tissue activation, and to define their pathogenetic roles in inflammation. Molecular characterization of the mediators CTAP III and V will be accomplished by protein fractionation guided by relevant bioassays and detailed characterization of the amino acid sequence and carbohydrate composition of the agonists. Structural studies of CTAP-IlI will concentrate on the significance of its isoelectric point microheterogeneity and glycosylation; studies of CTAP-V will concentrate on primary structure. This is crucial to design of competitive molecules and development of additional tactics for detailed study of these agents in clinical contexts. Immunostaining procedures and computer assisted image analysis will permit localization of CTAP-III and V in normal and pathologic tissues. Immunobinding and molecular biologic studies will define local formation of these growth factors. ELISA measurements of CTAP-III and V plasma levels will be correlated with rheumatic disease activity and the efficacy of drug interventions. Development of recombinant CTAP molecules and synthetic peptide fragments of both native and novel configuration offers an opportunity to develop new tactics to influence specific key sites in the inflammatory process. It will be important to define in greater detail the mechanism of action of CTAP mediators with focus on receptor studies, chemotaxis, collagenase formation and mechanisms controlling the biosynthesis and secretion of CTAP mediators. The ultimate goal of these studies is the development of agents or procedures capable of favorably modifying the inflammatory process in man. This includes suppressing the process (as in rheumatoid arthritis), and enhancing aspects of it (as in wound healing).